Apparatus for handling and drying pencil leads

ABSTRACT

Apparatus for handling and drying pencil leads comprising means for receiving the leads after extrusion and cutting thereof but while the leads are still moisture laden and hence limp and easily deformable, said means maintaining the leads in straightened condition while loading the leads into cylindrical cans, the loaded can being rotatable about their own axes to maintain the leads therein in straightened condition, the apparatus further comprising a rotary furnace for receiving the loaded cylindrical cans to effect drying of the leads, said rotary furnace comprising a rotor that slowly moves the loaded cans through an annular heating chamber, the loaded cans being mounted on discs which are rotatably mounted on the rotor, and drive means for simultaneously imparting rotation to the rotor and to the discs, the rotation of the latter being at a substantially greater rate than the rotation of the former, whereby as the rotor slowly carries the loaded cans through the heating chamber, the discs are simultaneously rotating about their own axes.

United States Patent 1191 Wiser et al.

11] r 3,791,504 [451 Feb. 12,1974

APPARATUS FOR HANDLING AND DRYING PENCIL LEADS Primary ExaminerEvon C.Blunk Assistant ExaminerDouglas D. Watts Attorney, Agent, or Firm-Salter& Michaelson [57 ABSTRACT Apparatus for handling and drying pencil leadscomprising means for receiving the leads after extrusion and cuttingthereof but while the leads are still moisture laden and hence limp andeasily deformable, said means maintaining the leads in straightenedcondition while loading the leads into cylindrical cans, the loaded canbeing rotatable about their own axes to maintain the leads therein instraightened condition, the apparatus further comprising a rotaryfurnace for receiving the loaded cylindrical cans to effect'drying ofthe leads, said rotary furnace comprising a rotor that slowly moves theloaded cans through an annular heating chamber, the loaded cans beingmounted on discs which are rotatably mounted on the rotor, and drivemeans for simultaneously imparting rotation to the rotor and to thediscs, the rotation of the latter being at a substantially greater ratethan the rotation of the former, whereby as the rotor slowly carries the9 loaded cans through the heating chamber, the discs are simultaneouslyrotating about their own axes.

7 Claims, 13 Drawing Figures PAIENIEDFEBI 21914 3.791.504

SHEET 3 BF 6 PAIENI FEB 1 2:914

saw a 0i 6 APPARATUS FOR HANDLING AND DRYING PENCIL LEADS This is adivision of application Ser. No. 879,381, filed Nov. 24, 1969 nowabandoned.

BACKGROUND OF THE INVENTION In the manufacture of pencil leads, the leadis first extruded and then cut to length. At this stage in themanufacturing process, the lead is limp and easily deformable andpossesses a high moisture content. The problem is to maintain the leadin substantially straight and unbroken form and at the same time removesubstantially all of the moisture therefrom, so that the lead will be inproper condition for the firing operation.

SUMMARY OF THE INVENTION The instant invention provides apparatus forovercoming the above mentioned problem. Generally speaking, the presentinvention comprises a combination of handling means and drying means.

The handling means comprises apparatus that re-' ceives the limp leadsand, while maintaining them in substantially straight and unbrokencondition, feeds the leads to a loading cup, which in turn transfers theleads to a cylindrical heating can. Means are provided for causing theloaded heating cans to rotate about their own axis prior to introductionof the loaded cans to the drying apparatus.

The drying apparatus comprises a rotary furnace having a rotor, theperipheral portion of which is enclosed by an annular heating chamber.Rotatably mounted on the rotor, adjacent the periphery thereof, are aplurality of discs, each of which has means for receiving a plurality ofloaded heating cans. The axes of the rotor, the discs, and of the leadsper se are all substantially'parallel to each other, and drive means areprovided for simultaneously rotating the rotor and the discs, therotation of the latter being at a substantially greater rate than thatof the former. Thus, as the rotor slowly rotates through the heatingchamber, the discs carrying the loaded cans are simultaneously rotatingabout their own axes, which in turn causes the leads within the cans toconstantly rotate about their own axes during the drying or heatingoperation.

DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the bestmode presently contemplated for carrying out the present invention: r r

FIG. 1 is a side elevational view of that portion of our apparatusrelating to the loading of the leads into the cylindrical heating cans;I

FIG. 2. is a top plan view thereof;

FIG. 3 is an enlarged fragmentary elevational view, partly in section,showing a part of the loading apparatus;

FIG. 4 is a fragmentary elevational view in section showing the loadingcup transferring leads to a heating can;

FIG. 5 is a fragmentaryplan view, partly in section, showing the nextstep during the transfer of the leads from the loading cup to theheating can;

FIG. 6 is a fragmentary elevational view, partly in section, showing themeans for rotating the loaded cans;

FIG. 7 is a schematic wiring diagram of the lead handling and loadingapparatus;

FIG. 8 is a perspective view of the rotary dryer that forms a part ofour apparatus;

FIG. 9 is an end elevational view thereof on an enlarged scale;

FIG. 10 is a side elevational view thereof, on an enlarged scale, with aportion broken away for purposes of illustration;

FIG. 11 is a fragmentary elevational view, on an enlarged scale, showingthe loading and unloading station of the dryer apparatus;

FIG. 12 is a perspective view showing one of the heating cans per se;and

FIG. 13 is a fragmentary perspective showing one of the disc assembliesin detail.

DESCRIPTION OF THE INVENTION FIGS. 1 through 7 illustrate the handlingand loading portion of our invention and specifically relate to theapparatus by which the extruded and cut leads are loaded intocylindrical cans within which the leads are subsequently heated anddried by a novel and unique rotary furnace which forms the second partof our invention. It will be understood that after the leads have beenextruded and cut, they have a high moisture content which must beremoved or at least substantially reduced before the leads can go to thefiring operation. Since the extruded lead is easily deformable, i.e.,having a consistency not unlike wet spaghetti, it is a considerableproblem to handle and load the leads while at the same time maintainingthem in. substantially straight and unbroken'condition. It is to thesolution of this problem that the first portion of our invention isdirected.

Referring to FIGS. 1 and 2, a table 10 has mounted thereon conveyormeans 12 comprising a plurality of side-by-side, spaced, endless belts14 extending around rollers 16 and 18 suitably journaled and mounted ontable 10 by means of supports 20. Roller 18 is driven by motor 22 bymeans of a suitable chain drive as shown most clearly in FIG. 1.

The leads 24, see FIG. 3, after having been extruded and cut and whilestill in a soft and deformable state, are positioned by any desiredmeans, manual or automatic, onto the end of conveyor 12 adjacent roller16, so that the-leads lie transversely or laterally across the belts 14.The conveyor 12, which is continuously being driven by motor 22 in aclockwise direction, carries the leads toward the end of the conveyoradjacent roller 18; and, as the leads move therealong, they are engagedby a flap 26 carried by a bracket 28 suitably mounted on table 10, itbeing noted that the engagement of the leads by the flap 26 causes theleads to be oriented into a single layer, as shown in FIG. 3, and at thesame time causes the leads to'extend substantially perpendicularlyacross the belts 14 while at the same time imparting some degree ofrotation to the leads about their own axes. The rotation of the leadsabout their own axes results in a self-straightening action that tendsto remove any defonnation or bowing of the leads.

When the leads reach the end of conveyor 12 adjacent roller 18, they arereceived by inclined guide means 30 which, together with side plates 32,serve to direct the leads into a loading cup 34. As willbe seen mostclearly in FIG. 3, the loading cup 34 is an openended cylinder,.alsohaving an open portion 36 at the top portion of itscircumference,through which the leads 24 pass from guide means 30.

Mounted to the table by any suitable means are a pair of air cylinders38 and 40 which are operable to impart reciprocal movement to holdingfingers 42 and 44, respectively. As will be seen most clearly in FIGS. 1and 3, the fingers 42 are located intermediate the rollers 16 and 18, itbeing understood that when the fingers 42 are in their downward oroperative position, as shown in FIG. 3, the fingers extend between thebelts 14 to interrupt and block further movement of the leads 24 alongconveyor 12. The fingers 44 cooperate with guides and are adapted tomove upwardly from the inoperative position shown in FIG. 3 to anoperative position wherein further flow of the leads 24 down the guides30 is interrupted and blocked, it being understood that the fingers 44extend upwardly between the guides 30. It will be understood that whenfingers 44 are retracted to their inoperative position, the fingers 42are in their downward or blocking position, and vice versa. Means areprovided for timing the operation of cylinders 38 and 40, and hencefingers 42 and 44, so that when the loading cup 34 has been filled tosubstantially a predetermined extent, cylinder will operate and movefingers 44 to a blocking position, while at the same time cylinder 38will cause fingers 42 to be retracted to an inoperative position.

Adjacent to the table 10 is a second table 46, the table 46 carrying anarcuate support 48 on which the loading cup 34 is slidably mounted. Itwill be understood that the support 48 is in alignment with conveyor 12so that under normal conditions the loading cup 34 is in position toreceive the leads 24 as they descend from the guides 30. The table 46 isactually laterally disposed with respect to support 48, and the table 46carries an upper inclined trackway 50 adapted to receive a plurality ofcylindrical heating cans 52, shown in detail in FIG. 12. The cans 52 areof suitable metallic construction, have a plurality of perforations 54in the side wall thereof, and are open at only one end, as at 56. Thecans 52 are mounted on the trackway 50 so that the open ends 56 thereofare disposed toward the laterally positioned loading cup 34. The emptycans 52 descend by gravity down trackway 50 until the lowermost can isreceived at a loading station 58, which is in lateral alignment withloading cup 34, as shown most clearly in FIG. 1. It is important to notethat the diameter of the loading cup 34 is somewhat less than thediameter of the cans 52, whereupon'the loading cup 34 may slidably moveinto the inside of the can 52, which is positioned at loading station58, by means now to be described.

As previously stated, the loading cup 34 is open at both ends, but theend farthest away from table 46 is normally closed by a circular plate60. An air cylinder 62 is connected to loading cup 34 by means of pistonrod 64 and connecting link 66, while another air cylinder 68 isconnected directly to plate 60. As will be seen most clearly in FIG. 2,connecting link 66 overlies the end of plate 60; whereupon when cylinder62 is operated to move the loading cup 34 into the can 52 located atstation 58, the plate 60 will move therewith, thus insuring that all ofthe leads positioned within cup 34 move laterally into the can 52located at the loading station. After the loaded cup 34 has been shiftedlatera'lly into the can 52 located at loading station 58, cylinder 62causes piston rod 64 to retract; while, at the same time, cylinder 68maintains the plate in its position within the can 52. Thus, the plate60 serves to hold the leads 24 within can 52 as the loading cup 34retracts, and hence, in effect, the cup 34 slides from beneath the leads24, the leads being held against movement by means of the plate 60.After the loading cup 34 has entirely retracted from can 52, cylinder 68then becomes operative to retract the plate 60, whereupon the can 52 inloading station 58 is now fully loaded, and the loading cup 34 and itsplate 60 are once again in position to receive another supply of leadsfrom conveyor 12. This particular means .for transferring the leads fromloading cup 34 to can 52 has proven to be particularly advantageous inthat the relatively soft leads are very gently deposited in can 52, thusresulting in minimal breakage and deformaof the leads during thistransferring operation.

As soon as can 52 has been loaded, as above described, and the loadingcup 34 and its plate 60 retracted, a further air cylinder 70 actuates akicker 72 which ejects the loaded can 52 onto a conveyor 74 whichcomprises an endless belt extending around rollers 76 and 78, the roller76 being chain driven by motor 22 in a clockwise direction. At the endof conveyor 74, adjacent roller 78, there is provided a stop means inthe form of a laterally extending roller 80, whereupon the loaded can 52is carried by conveyor 74 until it engages the roller 80 and then ismaintained thereby, although the continuous movement of conveyor 74,cooperating with the roller 80, causes the loaded can 52 to continuouslyrotate about its own axis. This continued rotation of the loaded cans 52further serves to maintain the loaded leads 24 in substantially straightcondition. As soon as a loaded can 52 is ejected from the loadingstation 58 onto conveyor 74, another empty can 52 drops by gravity intothe loading station, whereupon the aforedescribed loading operation isonce again repeated.

It will be understood that the air cylinders all operate in apredetermined timed sequence, the operation of each cylinder beingcontrolled by solenoids 38A, 40A, 62A, 68A, and 70A, see FIG. 7, whichin turn are energized by switches 38B, 40B, 62B, 68B, and 70B,respectively, said switches in turn being actuated by cams 38C, 40C,62C, 68C, and 70C, respectively, the cams being sequentially mounted ona cam shaft (not shown) which is driven by motor 22. FIG. 7schematically illustrates the simple circuit involved, it beingunderstood that a conventional circuit breaker is shown at 82, arheostat for controlling the speed of motor 22 is shown at 84, and apressure switch is shown at 86, whereby if there is not suitablehydraulic pressure in the system,

the circuit will automatically open to stop motor 22 and hence operationof the apparatus.

In summarizing the operation of the abovedescribed handling and loadingapparatus, it will be understood that the extruded and cut leads 24 arepositioned by any suitable means on conveyor 12 and are carriedtherealong until blocked by holding fingers 42 which are controlled bycylinder 38. With the holding fingers 42 in blocking or operativeposition, the holding fingers 44 are in their retracted or inoperativeposition, whereupon the leads 24 which have been carried by conveyor 12while fingers 42 were previously retracted are now free to descend downthe guide means 30 into loading cup 34. When a sufficient time haselapsed for cup 34 to become loaded to a desired degree, cam 40Cactuates switch 4013 to energizesolenoid 40A which in turn operatescylinder 40 to extend the fingers 44 to their blocking or operativeposition, thus preventing further leads from descending down the guidemeans 30. Simultaneously, cam 38C actuates switch 38B to energizesolenoid 38A which inturn operatescylinder 38 to retract the fingers 42to permit the leads 24 to once again be fed along conveyor 12 inpreparation for the next loading operation. When loading of cup 34 hasbeen completed, cam 62C actuates switch 62B to energize solenoid 62Awhich in turn operates cylinder 62 to move the loaded cup 34 laterallyinto the cam 52 located at the loading station 58. Operation of cylinder62 also causes end plate 62 to move with cup 34. After the cup 34 andend plate 60 have been moved into the can 52, cylinder 62 retracts thecup 34; but cylinder 68 maintains the plate 60 in its position near theopen end of cam 52. Thus, the plate 60 serves to maintain the leads 24within the cam 52 as the cup 34 slides outwardly from beneath the leads,whereupon the leads are gently deposited into can 52. After the cup 34has been completely retracted, cam 68C actuates switch 683 to energizesolenoid 68A which in turn operates cylinder 68 to retract the plate 60until it is once again positioned adjacent the end of cup 34 remote fromthe cans 52. As soon as plate 60 has been completely retracted, cam 70Cactuates switch 70B to energize solenoid 70A, which in turn causespiston 70 to operate kicker 72, which engages the cam 52 that has justbeen loaded and ejects same onto conveyor 74, the conveyor 74 carryingthe filled can until it reaches the end of conveyor 74 and abuts roller84, whereupon the filled can is caused to rotate about its own axis,pending removal for the next operation. At the same time, an-

other empty can descends into loading station 58, and the entireoperation is once again repeated.

Referring now to FIGS. 8 through 13, the apparatus which'receives theloaded cans 52 in order to effect heatingand drying of the leadscontained therein will now be described. This apparatus basicallycomprises a rotary furnace 88 which consists of a pair of large circularmetal plates 90, each approximately eight feet in diameter, which metalplates are mounted on a shaft 92, whichshaft is driven by a variablespeed motor 94 to impartrelatively slow rotation to said plates,approximately 93 minutes per revolution. Rotatably mounted on theoutside surfaces of each of the plates 90, and extending around theperipheral portion thereof, are a plurality of circular discs 96, eachof which has a plurality of spaced pins 98 extending outwardlytherefrom. The pins 98 are spaced from each other so as to providepockets for slidably receiving a plurality of the loaded cans 52, and,as shown in the drawings, each disc 96 is adapted to receive four cans52. The loaded cans 52 are slid into position on the discs 96 with theiropen ends 56 inwardly disposed, or abutting the discs 96, whereupon theleads within the cans 52 are complete] enclosed. I

As previously stated, the discs 96 are rotatably mounted on the plates90; and, more specifically, each pair of aligned discs is mounted on acommon shaft 100, as shown in FIG. 13, said shaft carrying a gear 102located intermediate the plates 90. Through suitable gearing, andbymeans of chain 104 and motor 105, the gears 102 are driven to impartrotation to shaft 100 and hence to the discs 96 carried thereby. Therate of rotation of shaft 100 and discs 96 is substantially greater thanthat of the plates 90, and, specifically, the discs 96 are rotated atapproximately 26 revolutions per minute. For reasons hereinafter to bedescribed, it is important to note that chain 104 does not makeengagement with a plurality of the gears 102; and, specifically, asshown in FIG. 10, there are always five gears 102 that are not beingdriven.

Fixedly mounted on the stanchions 106 are a pair of circular housings108, each defining an annular heat chamber. The housings 108 areidentical, and each is constructed of any desired refractory material,and comprises a peripheral end wall 1 10, a concentric inner wall 112,and a side wall consisting of a pair of removable panels 114. Theremovable panels 114 permit access to be had to any portion of theannular heating chamber for purposes of repair or the like.

At approximately the 4 oclock position of the annular heating chamber,two panels 114 are not provided, as shown in FIG. 11, thus creating aload and unload station. It is important to note that the annularhousing defined by the walls 110, 112 and 1.14 is fixedly mounted anddoes not rotate, although this annular housing does abut against theouter surface of the slowly rotating plate 90. Hence, the slowlyrotating plates carry the cans loaded thereon slowly through the annularchamber defined by the housings 108, while at the same time the discs 96are rotating about their own axes at a substantially greater rate. Anysuitable heating means may be provided within the annular housings108,although we prefer to use calrod heaters comprising rods 116 thatextend circumferentially around the inner-surface of the walls 110, withthe exception of the load and unload station shown in FIG. 11. In FIG.8, the wiring for the heating system is shown at 118 with terminalsboxes shown at 120 and with vent means shown at 122 for exhausting theheated atmosphere from the heat chamber.

The gears 102 that are not engaged by chain 104 are those gears whichare in alignment with the discs 96 located at the load and unloadstation, thus facilitating the loading and unloading of the cans 52. Itwill be understood that since plates 90 move so slowly, it is a simplematter to unload the cans 52 from each disc 96 as the discs descend intothe load and unload station, and at the same time to loadcans ofunheated lead onto the plates 96 before the plates enter into theheating chamber. The continuous rotation of the leads due to therotation of the discs 96 further enhances the straightening of the leadsand at the same. time results in complete drying of the leads, it beingunderstood that the perforations in the cans 52 also assist in insuringthat good circulation of heat is achieved within the cans. The speed ofrotation of the plates 90 and of the discs 96 may be varied, dependingupon the type and size lead being treated. It is also important to notethat the cams 52, when loaded, are not completely filled with leads,since the leads must be free to rotate within the cans as the cansrotate during various stages of the aforesaid operation. It also will beunderstood that although the furnace assembly 88 has been shown anddescribed as comprising a pair of plates 90 and annular heat chambers108, this is purely to increase capacity of the unit; and obviously ourinvention is equally applicable to a single unit or additional multipleunits.

While there is shown and described herein certain specific structureembodying the invention, it will be manifest to those skilled in the artthat various modifications and rearrangements of the parts may be madewithout departing from the spirit and scope of the underlying inventiveconcept and that the same is not limited to the articular forms hereinshown and described.

I claim:

1. Apparatus for handling and loading pencil leads into cylindrical canscomprising first conveyor means for continuously receiving a pluralityof leads laterally disposed with respect thereto, a cylindrical loadingcup positioned adjacent an end of said conveyor means, the cylindricalside wall of said cup having a longitudinally extending open portion forreceiving said laterally disposed leads therethrough, means fortransferring said leads from said conveyor means to said cylindricalloading cup, means for moving said filled loading cup into a cylindricalheating can and for retracting it therefrom, and means for maintainingsaid leads in said can during retraction of said cup therefrom.

2. In the apparatus of claim 1, second conveyor means, means forejecting said loaded can onto said second conveyor means, and meanscooperating with said second conveyor means for causing loaded canspositioned thereon to rotate around their own axes.

3. In the apparatus of claim 1, means cooperating with said firstconveyor means for straightening the leads thereon and orienting theleads into a single layer,

said means also causing the leads torotate about their own axes as theymove along said first conveyor means.

4. In the apparatus of claim 1, said transferring means comprisinginclined guides that receive the leads from said first conveyor meansand cause the leads to roll by gravity into said loading cup.

5. In the apparatus of claim 4, stop means cooperating with said firstconveyor means, said stop means being movable between an inoperativeposition and an operable position blocking passage of the leads to saidguides, and actuating means moving said stop means to said operableposition when said loading cup is filled to a predetermined degree.

6. In the apparatus of claim 1, said heating cans each comprising ametallic cylinder, open at one end, the circumferential wall of saidcylinder having a plurality of perforations therein.

7. In the apparatus of claim 2, said second conveyor means comprising anendless belt, said cooperating means comprising a roller mounted aboveand adjacent to said belt, said roller blocking further movement of thecans along said belt whereby the continuous movement of the beltcooperates with said roller to cause said blocked cans to rotate abouttheir own axes.

1. Apparatus for handling and loading pencil leads into cylindrical canscomprising first conveyor means for continuously receiving a pluralityof leads laterally disposed with respect thereto, a cylindrical loadingcup positioned adjacent an end of said conveyor means, the cylindricalside wall of said cup having a longitudinally extending open portion forreceiving said laterally disposed leads therethrough, means fortransferring said leads from said conveyor means to said cylindricalloading cup, means for moving said filled loading cup into a cylindricalheating can and for retracting it therefrom, and means for maintainingsaid leads in said can during retraction of said cup therefrom.
 2. Inthe apparatus of claim 1, second conveyor means, means for ejecting saidloaded can onto said second conveyor means, and means cooperating withsaid second conveyor means for causing loaded cans positioned thereon torotate around their own axes.
 3. In the apparatus of claim 1, meanscooperating with said first conveyor means for straightening the leadsthereon and orienting the leads into a single layer, said means alsocausing the leads to rotate about their own axes as they move along saidfirst conveyor means.
 4. In the apparatus of claim 1, said transferringmeans comprising inclined guides that receive the leads from said firstconveyor means and cause the leads to roll by gravity into said loadingcup.
 5. In the apparatus of claim 4, stop means cooperating with saidfirst conveyor means, said stop means being movable between aninoperative position and an operable position blocking passage of theleads to said guides, and actuating means moving said stop means to saidoperable position when said loading cup is filled to a predetermineddegree.
 6. In the apparatus of claim 1, said heating cans eachcomprising a metallic cylinder, open at one end, the circumferentialwall of said cylinder having a plurality of perforations therein.
 7. Inthe apparatus of claim 2, said second conveyor means comprising anendless belt, said cooperating means comprising a roller mounted aboveand adjacent to said belt, said roller blocking further movement of thecans along said belt whereby the continuous movement of the beltcooperates with said roller to cause said blocked cans to rotate abouttheir own axes.